Moulded Interconnect Devices (MID) integrate conductors and electrical circuits directly into three-dimensional plastic components which can be moulded practically at will. This makes the components both a housing and an electronic circuit in one. These injection moulded circuit carriers enable companies to develop components which are smaller, lighter and less expensive than is possible using classical circuit boards. Three dimensional MID systems are also simpler to mount and enable the integration of additional functions.
There can be hardly any other application which poses such widely differing demands on a compound than MID technology. LDS requires the compound to have high thermal resistance, good isotropic component behaviour and, most importantly, good capacity for metallization.
Low thermal expansion
Material developments are focused on the implementation of reduced conductor widths and improvement of thermal expansion and conduction. The choice of polymers is consequently restricted to highly thermally stable plastics. The matrix polymers used by Ensinger are polyphthalamides (PPA), polyetheretherketones (PEEK) and liquid crystal polymers (LCP). High-tech plastics are characterized by their excellent dimensional stability and rigidity, even at extremely high temperatures. LCP also comes with good chemical and flame-retardant properties, and is the thermosetting plastic with the lowest thermal expansion. The use of fillers further reduces expansion. Ensinger‘s newly developed compound TECACOMP LCP LDS 4107 expands approximately equally both in the direction of flow and also vertically to it.
Dural and firmly fixed metal pathways due to new fillers
During the LDS process, polymers are bonded to metals. The difficulty here is that plastics fundamentally demonstrate much higher thermal expansion than metal. If components are exposed to alternating thermal stress, there is a considerable risk of the conductor becoming detached over time.
3D HIPMAS Project
The MID manufacturing process is complex and comprises several production steps from the development of the base material, injection molding, metallization, assembly and quality assurance. In Community research, 12 international companies are developing a European pilot plant for 3-D micro-components by 2015. They have set themselves an ambitious goal: more than 50 percent of today's production costs are to be saved.
As part of the research project, Ensinger performed extensive test series in order to reconcile the material properties (thermal expansion) of polymers with those of the metal used. This has culminated in the development of special mineral and ceramic fillers which are new both in terms of their size and shape. The compound formulations optimized in this way ensure durable, firmly fixed and functionally reliable metal pathways.
3D HIPMAS is supported by the European Comission through ist Seventh Framework Program under the Public Private Partnership „Factories of the future“ initiative.